Azo dyestuffs containing a methylenesulfonylethanol radical or its sulfate ester



United States Patent This invention relates to a novel group of azodyestuffs, and more particularly to novel azo dyestuffs and theiruse-for dyeing polyamide fibers.

In the production of nylon fabric, the variation of tension of the warpin woven goods and variations in tension of knitting machines result inan increase in the number of crystalline regions in the nylon. Most acidwool dyes do not penetrate these crystalline regions in the nylonsufficiently during the dyeing operation to produce even or leveldyeings. The resulting objectionable barr effects are also thought to'bepartially due to variations in the temperature of heat setting of thenylon goods.

It is an object of this invention to provide novel dyestulfs which willnot be subject to the above disadvantages. Another object of thisinvention is the provision of novel azo dyestuffs which can be used fordyeing nylon and other polyamide fibers from an acidic aqueous medium toproduce dyeings exhibiting little or no barr and other objectionableeffects. Still another object of this invention is the provision of aprocess for producing polyamide dyeings exhibiting little or no barreffects and having im proved fastness to washing, and alkaline and acidperspiration. Other objects and advantages willappear as the descriptionproceeds.

The attainment of the above objects is made possible in accordance withthis invention by the provision of azo dyestuffs having the formulawherein Y is selected from the group consisting of H and $0 M, R isselected from the group consisting of H, lower alkyl and lower alkoxy, Xis selected from the group consisting of H and halogen, and M isselected from the group consisting of H, metal, ammonium, and aminecations. It has been found. that these dyestuffs can be appliedtopolyamide fibers from an acidic aqueous medium to produce level yellowdyeings exhibiting little or no barr effects and having good toexcellent fastness to Washing and/ or to alkaline and/ or acidperspiration.

. In the above formula, X may represent H, .Cl, Br, F,

or I, R may represent H, methyl, ethyl, methoxy, ethoxy or the like, andM may represent H, metal (including alkali metal and alkaline earthmetal) such as sodium, potassium, lithium, calcium, magnesium,strontium, barium, and aluminum, ammonium, or amine such as mono-, di-,and tri-methylamine, -ethylamine, -propylamine, -ethanolamine,' and-propanolamine, pyridinyl, and morpholinyl, and the like. M ispreferably alkali metal, particularly sodium and the CH SO CH CH OYgroup. is preferably in meta position relative to ,the azo bridge.

water-solubility than when Y is H, but this may in some cases beoutweighed by other considerations.

The above defined dyestufls maybe redaily prepared by coupling asuitable 2-, 4- or preferably 3-(3-methyl-5- oxo-2-pyrazolin-1-yl)benzene sulfonic acid in known manner with a diazotizedaminobenzylsulfonylethanol of the formula CH SO CIElI CHzOH wherein Rhas the values given above and the methylenesulfonylethanol group ispreferably in meta position relative to the amino group, followed bysulfation of the OH in said group. These diazo components may forexample be prepared by chloromethylation of a suitable substituted orunsubstituted nitrobenzene (as by reaction with bis chloromethyl etherin sulfuric acid), reaction of the result ing chloromethylatednitrobenzene with mercaptoethanol, oxidation of the resultingnitrobenzylthioethanol to the corresponding nitrobenzylsulfonylethanol(for example by reaction with hydrogen peroxide in the presence of atungstic acid catalyst as disclosed in U.S. 3,006,963), and reduction ofthe nitro group to amino (for example by treatment with iron or the likein sulfuric acid or the like).

The preferred diazo components containing the methylenesulfonylethanolgroup in'meta position relative to the amino group, and methods fortheir production, are disclosed and claimed in the copending applicationof Buc et a1., Serial No. 858,034, filed December 8, 1959, now PatentNo. 3,118,943. As examples of suitable diazo components, there may bementioned 2(2-methoxy-5- aminobenzylsulfonyl)ethanol of the formulaCHgSOzCHzCHgOH S aH 4-bromo 3 (3 methyl-5 -oxo-2-pyrazolin-l y1)benzenesulfonic acid, Q-chloro-S-(3-methyl-5-oxo-2-pyrazolin-1- When'Y is $0 M,the dyestuif exhibits somewhat better yl)benzene sulfonic acid,3-chloro-4-('3-methyl-5-oxo-2- pyraZolin-1-yl)benzene sulfonic acid,3-(3-methyl-5-oxo- 2-pyrazolin-1-yl)benzene sulfonic acid,4-(3-methyl-5- oxo-2-pyrazolin-1-yl)benzene sulfonic acid, and the like.

It will be understood that in the production of the dyestuffs of thisinvention wherein Y is H, a subsequent sulfation of the OH group in theabove described diazo components is omitted. On the other hand,dyestuifs of this invention wherein Y is M may also be prepared by firstsulfating the OH group of the described diazo component followed'bydiazotization thereof and coupling with the described pyrazalonecoupling component. This expedient of preliminary sulfation of the diazocomponent has certain advantages in that the amount of sulfating agentrequired is reduced, the water solubility of the diazo component isthereby improved, etc. Any usual sulfating agent may be employed,sulfuric acid being preferred.

The above defined dyestuffs of this invention are useful for dyeing(including printing) polyarnide fibers from an acidic aqueous medium,which latter term is intended to include solutions, dispersions, orstable or colloidal suspensions of the dyestuff adjusted to an acid pHand ap-.

propriately thickened in known manner when employed for printing. Theaqueous medium may be applied by jig dyeing, padding, spraying, printingor other suitable manner. A weakly acid medium is preferred, the pHgenerally ranging from about 3.5 to less than 7. Any acid may beemployed for adjustment of the pH, as for example formic, acetic,sulfuric, and the like. The temperature of application should range fromabout 140 F. up to the boiling point of the medium although highertemperatures may be employed when using a thermal dyeing processinvolving a subsequent curing step.

The dyestuffs of this invention are applicable for the dyeing of any ofthe synthetic linear condensation superpolyarnide fibers such as nylon,Perlon, Silon, Steelon,

Furon, and the like. For example, the nylon may be derived from adipicacid and hexamethylenediamine (Nylon 66), omega-aminocaproic acid (Nylon6), sebacic acid and hexamethylenediamine (Nylon 610), or mixtures orcopolymers thereof. The polyarnide fiber derived from polypyrrolidonemay likewise be dyed by the present process. Natural protein fibers suchas silk, goat and other animal hair, and particularly wool are readilydyed by the process of the present invention. Artificial regeneratedprotein fibers such as derived from casein, zein, or soya bean or thelike may also be dyed by the present process. Such regenerated proteinfibers are preferably of the hardened type as obtained for example byacetylation or treatment with formaldehyde.

Optimum results are obtained when the dyestuffs of this invention areapplied from an acidic aqueous bath at the defined elevated temperaturesto woven or knitted fabrics having a basis of nylon since by this methodthe described barre effects are minimized. The dyestuffs of thisinvention are substantive to the polyarnide and accordingly the fibersshould be allowed toremain in the dye bath until the dyestutf issubstantially completely exhausted.

Preferably, the dyeing process is carried out without addition of acidas described above until most of the-dyestuff has exhausted on to thefibrous material in order to promote levelness of the dyeing. Subsequentaddition of acid aids in obtaining complete exhaustion of the dyestuifon the fiber whereafter the dyeings are simply rinsed with water anddried.

The following example is only illustrative of this invention and is notto be regarded as limitative. All parts and proportions referred toherein and in the appended claims are by weight unless otherwiseindicated.

Example (a) Diazotization:

144 ml. of a solution of2(2-methoxy-5-aminobenzyl-sulfonyl)ethanol=0.075 mol. and

19.5 ml. concentrated hydrochloric acid, sp. gr. 1.189,

was cooled to 0-5 C. and diazotized by gradually adding with stirring 54ml. 10% wt./vol. sodium nitrite solution, maintaining the temperature at05 C. Stirring at 0-5" C. was continued for 10 minutes after theaddition of nitrite solution was complete. The excess nitrous acid(potassium starch-iodide paper test) was destroyed by the gradualaddition of 10 cc. 10% wt./vol. sulfamic acid solution. The diazosolution was made up to 300 ml. volume with water and one-third of thisdiazo solution (0.025 mole) was used in the coupling reaction.

Coupling reaction:

12.8 g. 4-chloro-3-(3-methyl-5-oxo-2-pyrazolin-lyl)benzene sulfonic acid(0.025 mole plus 5% excess) was dissolved in ml. water by the additionof 25 ml. 20% wt./vol. sodium canbonate solution. The solution (pH 7.0)was cooled to 10-l5 C. and with stirring 100 ml. (0.025 mole) of theprepared diazo solution of (a) above was added. The pH was 2.5.

25 ml. 20% wt./vol. sodium carbonate solution was gradually added tobring the pH to 8.8. After coupling was complete, the dyestutf wasprecipitated by the gradual addition of 50 g. sodium chloride, Theprecipitated dye was filtered and dried in a vacuum oven at 85 C.;Yield, 18.34 g.

Sulfate ester formation:

11.25 g. of the azo dye of (b) above was dissolved by adding graduallyto 78.75 g. of 96% sulfuric acid at room temperature with stirring. Inorder to insure complete solution the reaction mixture was stirred overnight. The sulfuric acid solution was drowned into 200 g. of ice and thedyestuff was precipitated by the gradual addition of 40 g. sodiumchloride. The dye mixture was stirred for an additional hour, thenfiltered. The cake was slurried in 150 ml. 20% wt./vol. sodium chloridesolution and the residual acid was neutralized by the addition of 10 g.sodium bicarbonate to pH 7.0.

1 ml. glacial acetic acid was added to reduce the pH to 6.6. Thedyestuff was filtered and dried in a vacuum oven at 85 C.; Yield 9.63 g.The dyestuff has the formula (d) Dyeing: 0.1 g. of the dyestulf of (0)above is added to 300 ml. water and the mixture is heated to F. 10 g.nylon piece goods is added to the dye bath and manipulated while thetemperature is increased to the boil and held at this temperature forone hour. 1% formic acid (based on the volume of the bath) is added andthe bath is held at the boil until the dyestuff is exhausted onto thenylon. The nylon piece goods is removed and rinsed with cold water.

The nylon is dyed a bright yellow shade having excellent wash fastness(wash test No. 3, AATCC) and alkaline and acid perspiration. The dyeingis level and free of barr effects.

This invention has been disclosed with respect to certain preferredembodiments and various modifications and variations thereof will becomeobvious to the person skilled in the art. It is to be understood thatsuch modifications and variations are to be included within the spiritand scope of this invention.

We claim: 1. An azo dyestuff of the formula cHisozcHz HzoY \N/ and $0 M,R is selected from the group consisting of H,

lower alkyl and lower alkoxy, X is selected from the group consisting ofH, chlorine and bromine, and M is selected from the group consisting ofH and alkali metal cations, the CH SO CH CH OY and $0 M groups being inone of the meta and para positions relative to the N- bonded cycliccarbon atom, and X being in one of the ortho and para positions relativeto the N-bonded cyclic carbon atom.

2. A dyestuif as defined in claim 1 wherein the CI-I SO CH CH OY groupis in meta position relative to the azo bridge.

. 6 3. A dyestuif as defined in claim 1 wherein Y is $0 M, R is loweralkoxy, X is chlorine, and M is sodium.

4. An azo dyestuif of the formula O=C CHZSOQCHjCHZOSOgNQ \N/ SO NaReferences Cited in the file of this patent UNITED STATES PATENTS2,347,143 Wilcoek Apr. 18, 1944 2,371,536 MacGregor Mar. 13, 19452,424,493 Muller et a1 July 22, 1947 2,657,205 Heyna et al. Oct.27, 19532,728,762 Heyna et al. Dec. 27, 1955 2,880,117 Lyons et al Mar. 31, 19592,895,785 Alsberg et al July 21, 1959 3,094,516 Randall et a1. June 18,1963 FOREIGN PATENTS 628,971 Canada "Oct. 10, 1961 1,181,107 France Jan.5, 1959 UNITED STATES PATENT OFFICE 7 CERTIFICATE OF CORRECTION PatentNo. 3,170,912 February 23, 1965 Harlan B. Freyermuth et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 2, line 3, for "redaily" read readily column 6, line 22, for"2,880,117" read 2,880,177

Signed and sealed this 21st day of January 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting, OfficerCommissioner of Patents

1. AN AZO DYESTUFF OF THE FORMULA